    Patent Document 1: JP-2007-156950A    Patent Document 2: JP-2007-272596A (US2007/0230929)    Patent Document 3: JP-2000-6687A    Patent Document 4: JP-2007-198574A    Patent Document 5: JP-2000-106069A    Patent Document 6: JP-2003-346162A
A remote controller has been long known as an apparatus for operating onboard apparatuses such as a car navigation system. The remote controller may be inconvenient in such points that a user gropes for the remote controller, holds it in his or her hand, and presses buttons. To solve this problem, various technologies are proposed.
For example, Patent Documents 1 through 6 disclose prompter-based remote controlling apparatuses using a touch panel and a camera. The technologies provide an armrest with a touch panel and provide a monitor at a dash panel, for example, or at an easily viewable position away from the touch panel. The camera is placed over or below the touch panel and captures manual operations on the touch panel. The camera captures a driver's finger shape image on the touch panel. The captured image is displayed at, for example, an instrument panel of the vehicle, that is, a position where the driver can easily view with minimal movement of the line of sight. In other words, the technologies superimpose the captured finger image as is or processed on a graphical user interface image (such as an operation menu) displayed on a monitor.
The following describes a first problem about the above-mentioned prompter-based remote controlling apparatus.
According to the technologies described in Patent Documents 1 and 2, an operator differently feels forces for turning on switches. This is because a contact area on the touch panel depends on an angle of the operator's finger. The distance between a fingertip and a touch position varies because operators vary angles of their fingers that press the touch panel.
The prompter-based remote controlling apparatus may cause an unintended or inadvertent input operation such as an input error due to variations in touch inputs by an operator.
The following describes a second problem about the above-mentioned prompter-based remote controlling apparatus.
A conventional prompter-based input apparatus features a small number of operations or operation frequency compared to steering wheel or accelerator pedal operations. However, the conventional input apparatus consumes much electric current because a video camera is always powered or a touch panel is always ready for operations. The current is supplied from a battery or an alternator of the vehicle. This may increase electricity generated or degrade the regeneration efficiency for hybrid cars.
The following describes a third problem about the above-mentioned prompter-based remote controlling apparatus.
The above-mentioned input apparatus provides a remote operation section within reach of the operator independently of a display apparatus for displaying an operation screen (main screen). Further, the input apparatus captures and extracts a hand that operates the remote operation section. The input apparatus reflects the acquired hand image and movement on the operation screen (main screen) of the display apparatus. The input apparatus controls the display as if the operator directly touched the operation screen. When the input apparatus is provided for a vehicle, the remote operation section is placed within reach of a user sitting on the seat so as to improve operability of the input apparatus. The remote operation section is often provided with a touch-based or contact-based operation panel including a touch operation surface.
When the operation panel is provided in a vehicle compartment, it is highly likely that various operation sections are placed around the operation panel. The operation section may represent a press operation section such as a push switch or a seesaw switch that detects a specified pressure displacement. In such case, the user may extend his or her hand to the operation panel for touch operation but may inadvertently touch the press operation section to cause an operational error. Pressing or touching the press operation section just signifies whether or not an operation knob deflects. The operation concerns the same direction and is more likely to cause an operational error than the case of placing the other operation sections.
The following describes a fourth problem about the above-mentioned prompter-based remote controlling apparatus.
Patent Document 2 discloses the mechanism of the prompter-based input apparatus as follows. The apparatus allows an operator to touch an operation surface for input. The operation surface uses a transparent sheet. A lighting section and an imaging section are provided opposite to the operator with reference to the operation surface. The lighting section lights the operator's hand or finger that touches the operation surface. The imaging section captures an image of the hand or finger and analyzes the image to determine the content of the operator's input.
For example, Patent Document 6 discloses the hand image recognition system available for prompter-based input apparatuses. The system generates a hand area extraction image and a hand area fine-line image from an image captured by the camera. The system recognizes an input instruction by extracting apparent features such as a finger diameter from the hand area extraction image and extracting a hand direction and a finger coordinate from the hand area fine-line image.
When the camera and the LED are placed along the same axis as conventionally practiced, the captured image may include an image of the light source of the lighting section. This may degrade the accuracy of image analysis for recognizing an operation content.